I am burning Blaschak nut coal in my Harman Elite Magnafire insert. After numerous attempts to start the fire, I have finally succeeded, however I can only keep it burning for 10 - 12 hours. My goal is to heat my home with this insert. Am I choking the fire by putting too much coal on it after it has a good burn going? I also need to keep my lower vent door open or it does not get enough air and goes out. Is there too much ash content that would smother the fire? I do the shaking of the grate as per instructions. My coal is angled high to the back of the insert and lower to the front of the door. How much coal is a full load for this insert? Is 25 lb adequate? How long should this burn before I refill? Would the "refill" be another 25lb? I would appreciate any comments from other users. I seem to be stumped.

You need to fill the fire box up to the top of the brick with coal. Fill it a few shovels at a time letting them get burning good then a few more so on so on. It should hold 70lb +/- When you shake the fire don't stop till you have a nice glow from underneath the grates.

Thank you for replying to my questions, but I have a couple more. How long should burn time be with a full coal load?When you say I should shake the coals, at what point and frequency do you recommend? I seem to get 10 - 12 hours burn time, then it fizzles out. Should I shake after 12 hours until I get red coals in the ash pan? Do I refill coal after shaking?

You won't smoother your fire with "coal", but with "ash accumulation". You can shake it anytime there may be an over abundance of ash below the coal. Also, I recommend poking the fire from above to loosen it and provide some airways.